/*
 * Copyright (C) 2005-2011 MaNGOS <http://www.getmangos.com/>
 *
 * Copyright (C) 2008-2011 Trinity <http://www.trinitycore.org/>
 *
 * Copyright (C) 2010-2011 ProjectSkyfire <http://www.projectskyfire.org/>
 * 
 * Copyright (C) 2011 ArkCORE <http://www.arkania.net/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "ModelInstance.h"
#include "WorldModel.h"
#include "MapTree.h"
#include "VMapDefinitions.h"

using G3D::Vector3;
using G3D::Ray;

namespace VMAP {
ModelInstance::ModelInstance(const ModelSpawn &spawn, WorldModel *model) :
		ModelSpawn(spawn), iModel(model) {
	iInvRot = G3D::Matrix3::fromEulerAnglesZYX(G3D::pi() * iRot.y / 180.f,
			G3D::pi() * iRot.x / 180.f, G3D::pi() * iRot.z / 180.f).inverse();
	iInvScale = 1.f / iScale;
}

bool ModelInstance::intersectRay(const G3D::Ray& pRay, float& pMaxDist,
		bool pStopAtFirstHit) const {
	if (!iModel) {
		//std::cout << "<object not loaded>\n";
		return false;
	}
	float time = pRay.intersectionTime(iBound);
	if (time == G3D::inf()) {
//            std::cout << "Ray does not hit '" << name << "'\n";

		return false;
	}
//        std::cout << "Ray crosses bound of '" << name << "'\n";
	/*        std::cout << "ray from:" << pRay.origin().x << ", " << pRay.origin().y << ", " << pRay.origin().z
	 << " dir:" << pRay.direction().x << ", " << pRay.direction().y << ", " << pRay.direction().z
	 << " t/tmax:" << time << "/" << pMaxDist;
	 std::cout << "\nBound lo:" << iBound.low().x << ", " << iBound.low().y << ", " << iBound.low().z << " hi: "
	 << iBound.high().x << ", " << iBound.high().y << ", " << iBound.high().z << std::endl; */
	// child bounds are defined in object space:
	Vector3 p = iInvRot * (pRay.origin() - iPos) * iInvScale;
	Ray modRay(p, iInvRot * pRay.direction());
	float distance = pMaxDist * iInvScale;
	bool hit = iModel->IntersectRay(modRay, distance, pStopAtFirstHit);
	if (hit) {
		distance *= iScale;
		pMaxDist = distance;
	}
	return hit;
}

void ModelInstance::intersectPoint(const G3D::Vector3& p,
		AreaInfo &info) const {
	if (!iModel) {
#ifdef VMAP_DEBUG
		std::cout << "<object not loaded>\n";
#endif
		return;
	}

	// M2 files don't contain area info, only WMO files
	if (flags & MOD_M2)
		return;
	if (!iBound.contains(p))
		return;
	// child bounds are defined in object space:
	Vector3 pModel = iInvRot * (p - iPos) * iInvScale;
	Vector3 zDirModel = iInvRot * Vector3(0.f, 0.f, -1.f);
	float zDist;
	if (iModel->IntersectPoint(pModel, zDirModel, zDist, info)) {
		Vector3 modelGround = pModel + zDist * zDirModel;
		// Transform back to world space. Note that:
		// Mat * vec == vec * Mat.transpose()
		// and for rotation matrices: Mat.inverse() == Mat.transpose()
		float world_Z = ((modelGround * iInvRot) * iScale + iPos).z;
		if (info.ground_Z < world_Z) {
			info.ground_Z = world_Z;
			info.adtId = adtId;
		}
	}
}

bool ModelInstance::GetLocationInfo(const G3D::Vector3& p,
		LocationInfo &info) const {
	if (!iModel) {
#ifdef VMAP_DEBUG
		std::cout << "<object not loaded>\n";
#endif
		return false;
	}

	// M2 files don't contain area info, only WMO files
	if (flags & MOD_M2)
		return false;
	if (!iBound.contains(p))
		return false;
	// child bounds are defined in object space:
	Vector3 pModel = iInvRot * (p - iPos) * iInvScale;
	Vector3 zDirModel = iInvRot * Vector3(0.f, 0.f, -1.f);
	float zDist;
	if (iModel->GetLocationInfo(pModel, zDirModel, zDist, info)) {
		Vector3 modelGround = pModel + zDist * zDirModel;
		// Transform back to world space. Note that:
		// Mat * vec == vec * Mat.transpose()
		// and for rotation matrices: Mat.inverse() == Mat.transpose()
		float world_Z = ((modelGround * iInvRot) * iScale + iPos).z;
		if (info.ground_Z < world_Z) // hm...could it be handled automatically with zDist at intersection?
				{
			info.ground_Z = world_Z;
			info.hitInstance = this;
			return true;
		}
	}
	return false;
}

bool ModelInstance::GetLiquidLevel(const G3D::Vector3& p, LocationInfo &info,
		float &liqHeight) const {
	// child bounds are defined in object space:
	Vector3 pModel = iInvRot * (p - iPos) * iInvScale;
	//Vector3 zDirModel = iInvRot * Vector3(0.f, 0.f, -1.f);
	float zLevel;
	if (info.hitModel->GetLiquidLevel(pModel, zLevel)) {
		// despite making little sense, there ARE some (slightly) tilted WMOs...
		// we can only determine liquid height in LOCAL z-direction (heightmap data),
		// so with increasing tilt, liquid calculation gets increasingly wrong...not my fault, really :p
		liqHeight = (zLevel - pModel.z) * iScale + p.z;

		return true;
	}
	return false;
}

bool ModelSpawn::readFromFile(FILE *rf, ModelSpawn &spawn) {
	uint32 check = 0, nameLen;
	check += fread(&spawn.flags, sizeof(uint32), 1, rf);
	// EoF?
	if (!check) {
		if (ferror(rf))
			std::cout << "Error reading ModelSpawn!\n";
		return false;
	}
	check += fread(&spawn.adtId, sizeof(uint16), 1, rf);
	check += fread(&spawn.ID, sizeof(uint32), 1, rf);
	check += fread(&spawn.iPos, sizeof(float), 3, rf);
	check += fread(&spawn.iRot, sizeof(float), 3, rf);
	check += fread(&spawn.iScale, sizeof(float), 1, rf);
	bool has_bound = (spawn.flags & MOD_HAS_BOUND);
	if (has_bound) // only WMOs have bound in MPQ, only available after computation
	{
		Vector3 bLow, bHigh;
		check += fread(&bLow, sizeof(float), 3, rf);
		check += fread(&bHigh, sizeof(float), 3, rf);
		spawn.iBound = G3D::AABox(bLow, bHigh);
	}
	check += fread(&nameLen, sizeof(uint32), 1, rf);
	if (check != (has_bound ? 17 : 11)) {
		std::cout << "Error reading ModelSpawn!\n";
		return false;
	}
	char nameBuff[500];
	if (nameLen > 500) // file names should never be that long, must be file error
			{
		std::cout << "Error reading ModelSpawn, file name too long!\n";
		return false;
	}
	check = fread(nameBuff, sizeof(char), nameLen, rf);
	if (check != nameLen) {
		std::cout << "Error reading ModelSpawn!\n";
		return false;
	}
	spawn.name = std::string(nameBuff, nameLen);
	return true;
}

bool ModelSpawn::writeToFile(FILE *wf, const ModelSpawn &spawn) {
	uint32 check = 0;
	check += fwrite(&spawn.flags, sizeof(uint32), 1, wf);
	check += fwrite(&spawn.adtId, sizeof(uint16), 1, wf);
	check += fwrite(&spawn.ID, sizeof(uint32), 1, wf);
	check += fwrite(&spawn.iPos, sizeof(float), 3, wf);
	check += fwrite(&spawn.iRot, sizeof(float), 3, wf);
	check += fwrite(&spawn.iScale, sizeof(float), 1, wf);
	bool has_bound = (spawn.flags & MOD_HAS_BOUND);
	if (has_bound) // only WMOs have bound in MPQ, only available after computation
	{
		check += fwrite(&spawn.iBound.low(), sizeof(float), 3, wf);
		check += fwrite(&spawn.iBound.high(), sizeof(float), 3, wf);
	}
	uint32 nameLen = spawn.name.length();
	check += fwrite(&nameLen, sizeof(uint32), 1, wf);
	if (check != (has_bound ? 17 : 11))
		return false;
	check = fwrite(spawn.name.c_str(), sizeof(char), nameLen, wf);
	if (check != nameLen)
		return false;
	return true;
}
}
